1. Field of the Invention
The present invention relates to methods and apparatus for audience rating systems for digital television and radio.
2. Description of the Prior Art
The television and radio industries and commercial advertisers have an obvious interest in knowing how many people are watching or listening to particular stations and programs. Various systems of audience rating have been developed for analog television and radio, of which the most accurate use a meter that is connected to the television set or radio, that records when the receiver is turned on and off, and what channels or frequencies it is tuned to. Digital television and radio are now being introduced, and are expected to eventually completely replace analog television and radio. The existing rating devices for analog televison and radio either will not work at all with digital television and radio, or will work only poorly. The present invention is a method of audience rating for digital television and radio, that uses an apparatus that can be connected to a digital televison set or radio. It makes use of identification codes in the control stream of multiplexed digital transmissions to record the channel being received.
U.S. Pat. No. 4,547,804, issued on Oct. 15, 1985, Burton L. Greenberg, discloses a method and apparatus for the automatic identification and verification of commercial broadcast programs. A digital encoded identifying number is embedded in the programs, by which they can be automatically monitored, to verify that they have been broadcast as and when intended. However, the digital number is embedded in what is otherwise an analog program. This method is usable only during the transition period from analog to digital broadcasting technology, when some digital equipment or connection is in use together with older analog equipment or connections. It will not work when the broadcasting stations have fully digital operations, e.g., recording a program in digital form, storing it digitally on tape or disk, performing nonlinear digital edits and digital commercial insertions, and transmitting digitally in the air, or delivering a digital stream to a cable or satellite operator to multiplex with other digital streams. The instant invention is distinguishable, in that it is fully digital and will work with broadcasting that is fully digital, and it is designed for audience ratings, rather than broadcast verification.
U.S. Pat. No. 4,647,974, issued on Mar. 3, 1987, to Robert J. Butler and Ronald G. Schlameuss, discloses a system for the automatic insertion of auxiliary video information into an analog television signal. The system may be used by a local station to insert its call letters or logo into network programming. The instant invention is distinguishable, in that it uses digital signals in digital broadcasts, and is designed to monitor receivers.
U.S. Pat. No. 4,697,209, issued on Sep. 29, 1987, to David Kiewit and Daozheng Lu, discloses a method and apparatus for identifying television programs, by detecting the occurrence of events such as scene changes in a video signal, and extracting a signature from the signal. Signatures and their times of occurrence are stored and compared with reference signatures to identify the program. As the system is independent of the format used to transmit the signal, it will work with both analog and digital television. It has the disadvantage of requiring that a large volume of reference data be collected for every possible station and program being transmitted, and for every site monitored, which will require a large computing capacity and a long computing time to correlate the two sets of data to determine which station or program is being received at each monitored site at each instant that each receiver is turned on. The instant invention is distinguishable, in that it is designed to monitor the reception of digital transmissions only, and will work efficiently with such transmissions, by using identification codes in their control streams.
U.S. Pat. No. 4,972,503, issued on Nov. 20, 1990, to Everett V. Zurlinden, discloses a method and apparatus for determining the channel to which a remotely controlled television receiver is tuned. While it is independent of the format (analog or digital) used to transmit the signal, its implementation on a mass scale for audience ratings will not be practical, as it requires an individual hardware or software adaptation to each remote control used in the monitored sites to determine what function is activated when a key pressing is detected. The instant invention is distinguishable, in that requires no such adaptation to remote controls, and may be implemented even if a remote control is not used.
U.S. Pat. No. 5,019,899, issued on May 28, 1991, to Glenn M. Boles et al., discloses an electronic data encoding and recognition system for creating digital signatures from frames of selected video segments such as television commercials by a digitalizing, compression and selection process which produces a multi-digit signature from each frame. The instant invention is distinguishable, in that it uses digital signals in digital broadcasts, and may be used to monitor receivers.
U.S. Pat. No. 5,278,988, issued on Jan. 11, 1994, to Jean P. Dejean, Enrico Massetti, Ken Straub and Everett Zurlinden, discloses a method and apparatus for determining the transmitting station from which analog program signals are received and translated by a monitored receiver within a test area. The instant invention is distinguishable, in that it is designed to detect and. record the reception of digital transmissions by digital receivers.
U.S. Pat. No. 5,425,100, issued on Jun. 13, 1995, to William L. Thomas, Paul C. Kempter and David H. Harkness, discloses a multi-level encoded signal monitoring system and a universal broadcast code for identifying programs, commercial, networks, stations, etc. The instant invention is distinguishable, in that it is designed for and will work with fully digital programming, and does not require multiple levels of encoding.
U.S. Pat No. 5,450,122, issued on Sep. 12, 1995, to Leonard D. Keene, discloses an in-station method and apparatus for encoding analog television programs, including commercials, with a digital identification code recorded on a selected video scan line which is not normally visible to the television viewer, and for verifying the proper airing of such programs by television broadcast stations. The instant invention is distinguishable, in that it is designed for determining audience ratings for digital television and radio.
U.S. Pat. No. 5,450,490, issued on Sep. 12, 1995, to James M. Jensen et al., discloses apparatus and methods for including an inaudible code in an analog audio signal, and for decoding it. The instant invention is distinguishable, in that it uses identification codes in the control streams of multiplexed digital transmissions.
U.S. Pat. No. 5,512,933, issued on Apr. 30, 1996, to Mark A. Wheatley and Peter Wilcox, discloses a system for identifying a program stream being displayed at a receiver location, by measuring the relative luminance of a plurality of predetermined areas in each frame of a television transmission, at both the transmitting station and the receiver. As the system is independent of the format used to transmit the signal, it will work with both analog and digital television. But, as with Kiewit et al., supra, it has the disadvantage of requiring that a large volume of reference data be collected for every possible station and program being transmitted, and for every site monitored, as well as requiring a large computing capacity and a long computing time to correlate the two sets of data to determine which station or program has been received at each monitored site at each instant that the receiver was turned on. As before, the instant invention is distinguishable, in that it is designed to monitor the reception of digital transmissions only, and will work efficiently with such transmissions, by using identification codes in their control streams.
U.S. Pat. No. 5,574,962, issued on Nov. 12, 1996, to Michel Fardeau et al., discloses a method and apparatus for automatically identifying a program, by adding an inaudible encoded message to the audio signal. The instant invention is distinguishable, in that it is designed for multiplexed digital transmissions, and uses identification codes already present in their control streams.
U.S. Pat. No. 5,646,675, issued on Jul. 8, 1997, to Robert C. Copriviza et al., discloses a system and method for monitoring the reception of video program material, using codes inserted on scan lines. Again, the instant invention is distinguishable, in that it is designed for multiplexed digital transmissions, and uses identification codes already present in their control streams.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.